They haven’t collapsed. At least not yet.

On Aug. 9, the Red Sox were not only comfortably in first place by 2½ games over the Yankees, but they also enjoyed a significant safety net. Should the Yankees leapfrog them, the Sox still enjoyed an extremely comfortable margin of 8½  games in the wild card over the Angels, and 11 games over the Rays.

By Sept. 4, when the Sox left Fenway for a two-city, seven-game journey, the Sox had slipped 1½ games behind New York in the AL East. Even so, their passage to the postseason seemed secure, given that they stood eight games in front of the Rays in the wild card and 8½ ahead of the Angels.

On Sunday, the Sox flew home after a 1-6 road trip that was punctuated with a sledgehammer, a three-game sweep at the hands of the Rays that left the Sox in possession of a 3½ game lead in the wild card that felt like far less than that. The Rays have smoked the Sox for five straight wins, with Tampa Bay’s pitching staff having dominated the Boston lineup. 

Because the Rays control their own destiny, with four more head-to-head games against the Sox next starting on Thursday at Fenway, the gap seems strikingly narrow, a fact that the Sox have been forced to acknowledge.

“If we keep on playing like that,” DH David Ortiz told reporters of the three-game sweep, “we’ll be at home in October.

“At this point,” Ortiz added, “you panic. Hell yeah. You’ve got to panic at this point. But you’re not going to do anything panicking but [instead by] playing better.

“Of course you’re freaked out. You go on this road trip 1-6, it’s not good. We’ve got these guys breathing down our necks and we’re not in first place either. We’ve got to come back and play better.”

Undoubtedly, all things being equal, the Sox would rather be the hunted rather than the hunter, even with their recent poor play. That said, they are also at the point where a collapse -- seemingly inconceivable as the Sox were steamrolling their way through the season on a 100-win pace -- has now become not only real but palpable.

But how? What took the Sox from a victory march into the postseason to a position in which they are suddenly desperate to regain a toehold amidst their downward slide?

In the first 11 days of September, the conversation of the Sox has shifted dramatically from one of whether they are good enough to do any damage in the postseason to whether they are good enough to get there. Here is a breakdown of the anatomy of a 10-game September stretch that has altered the tenor of the Sox’ season completely.

FOR STARTERS …

The Red Sox rotation has endured a turn unlike anything seen in a decade.

Jon Lester was supposed to ensure that the Sox would not go through a stretch like this, even at a time when co-ace Josh Beckett and newly acquired middle-of-the-rotation starter Erik Bedard were unavailable due to injuries. But instead, Lester showed up for a pivotal contest with flat stuff. The result was a 43-pitch first inning that laid the groundwork for a four-inning outing, tied for Lester’s shortest of the season.

And that, in turn, meant that the Sox endured a full five-game run in which no starter recorded a single out in the fifth. Tim Wakefield was touched for five runs in five innings on Wednesday; Andrew Miller allowed five in five the next day; John Lackey needed just three innings to permit his five runs on Friday against Tampa Bay; Kyle Weiland held the Rays to three runs but lasted just four innings on Saturday; and finally, Lester gave up four runs in four innings on Sunday.

The last time the Sox suffered such a rut? That would be Sept. 21-25, 2001, when Casey Fossum, Hideo Nomo, David Cone, Derek Lowe and Frank Castillo went through such a spell.

The absences of Bedard and Beckett have been impactful. Those two regularly delivered quality starts. In their absence, the only member of the Sox who can reliably offer such outings is Lester.

And so, when he falters -- as he did on Sunday -- it becomes magnified, because Wakefield, Lackey, Miller and Weiland have combined have produced quality starts (six or more innings, three or fewer earned runs) in just 20 of their combined 60 outings -- a 33 percent rate that is significantly below the major league average of 54 percent.

Those shortcomings have been glaringly apparent this month. In their 11 games in September, Sox starters have delivered just 49 innings (an average of 4.5 innings per contest) while forging a collective 6.80 ERA. That has not only left the Sox to struggle to a 2-9 mark this month, but has created an enormous tax on Red Sox relievers.

Speaking of:

NO RELIEF IN SIGHT

The Sox have pitched exactly as many relief innings this month (49) as they have received from their starters. And they have gotten comparable effectiveness from their bullpen members, with the relievers combining to produce a 6.43 ERA.

Between the starters and relievers, the Sox’ 6.61 ERA this month is easily the worst in the majors.

The bullpen instability has begun with Daniel Bard, who has given up runs in three of four outings, blowing two saves and absorbing two losses. The right-hander has a 17.18 ERA in his four appearances this month.

Behind Bard, Matt Albers -- who had emerged for the first four months of this year as the bridge to Bard -- has continued a horrific six-week stretch into September. He entered the game on Sunday with the bases loaded and immediately unloaded them by giving up a grand slam to B.J. Upton. Albers has now been relegated to garbage time, and he’s given few indications of re-emerging as a pitcher who can be entrusted with key innings.

The pitcher who appeared most likely to assume Albers’ role as a key late-innings contributor has also stepped backwards in September. Dan Wheeler has given up runs in each of his last three outings. Interestingly, he did not pitch at all against Tampa Bay, perhaps a suggestion that the Sox wanted to step off the gas pedal with the 33-year-old.

In short, Jonathan Papelbon has been great, Franklin Morales (who is rarely used in meaningful situations) has held the opponent scoreless in 12 of his last 13 appearances (though he has allowed four of eight inherited runners to score), Alfredo Aceves has been used as both a setup man and a long man…and the rest of the relief corps has struggled badly.

Unlike the rotation, the issue with the bullpen has not been health (at least not that anyone is aware of). It is simply that the pitchers who are there have fallen into a collective struggle at the wrong time for the team.

THE GRINDERS ARE MISSING

The Sox have actually received huge performances from a number of their name players in September. Jacoby Ellsbury extended his hitting streak to 16 games on Sunday, during which he is hitting .338 with a .429 OBP, .662 slugging mark and 1.091 OPS. Adrian Gonzalez is once again driving the ball, hitting .303/.465/.606/1.071 this month. David Ortiz is hitting .310 with a .408 OBP in September.

But whereas the Sox had five players performing at the level of All-Stars through July and even into August, the team has been missing a pair of players who in many way embody the Sox’ relentless, grinding offensive approach.

Kevin Youkilis struggled in five games after returning from the DL to rest his back strain. He has since been diagnosed with a sports hernia that will not be fully addressed until the offseason.

In the interim, the Sox are hopeful to get him back in the lineup in the coming days. That said, it remains to be seen whether he can return to his prior status as a middle of the order force, or if he’ll be the guy who hit .185 with a .572 OPS this month.

Then there is Dustin Pedroia, whose MVP candidacy is no longer a topic of discussion. The second baseman is now just 3-for-34 (.088) with nine strikeouts in his last eight games.

Opponents are exploiting their absences. Ellsbury has walked six times in 11 games this month; he’s on pace to get more free passes than in any other month this year. Gonzalez, likewise, has walked nine times this month. Ortiz has walked on eight occasions.

Whereas the top five spots in the order represented a wall that opponents found nearly impossible to vault, the absence of Youkilis and struggles of Pedroia have changed the complexion of the Sox lineup.

That, in turn, has created significant inconsistency in the offense. The Sox have 54 runs this month, good for a respectable 4.9 runs per game that ranks fourth in the AL. But in five games, the team has scored two or fewer runs, giving a struggling pitching staff little room to maneuver.

SLOPPINESS

The Sox are a startling 2-for-6 in stolen base attempts this month, and Mike Aviles added to the outs being given away on Sunday when he was picked off by Rays starter James Shields.

The Sox have committed seven errors in their last eight games, a span in which they’re 1-7. They have also made poor defensive decisions that have not resulted in errors but that have benefited their opponents, as on Saturday, when both Carl Crawford and Josh Reddick missed cutoff men to permit the Rays to claim extra bases.

And then there was the ball that fell between Jacoby Ellsbury and Darnell McDonald that turned into a leadoff triple in the 11th inning on Saturday. Ellsbury suggested the ball was catchable; the center fielder may have pulled up on the play.

“We haven’t executed anything,” second baseman Dustin Pedroia told reporters in St. Petersburg. “We haven’t swung the bat good, we haven’t pitched good, we haven’t played good defense. When you don’t do that, it doesn’t matter what level you’re playing at, you’re going to get beat.

“If we don’t, we’re going to go home, that’s basically it,” he added. “If we don’t play well, we go home.”

ALL OF THAT SAID, THE FULL-ON FREAKOUT MAY BE PREMATURE

The fact that the Sox are now talking openly of the consequences of failure is little short of startling.

The 1995 Angels are the standard-setter in collapses, having choked away an 11½ game lead to the Mariners that saw them go from a 99.9 percent lock to make the playoffs to October spectator. The 1951 Dodgers hacked up a 12½ game lead over the Giants, who cheated their way to a pennant on Bobby Thomson’s historic homer, thus making a mockery of the notion that Brooklyn held a 99.7 percent chance of reaching the World Series.

The Sox, according to coolstandings.com, had a 99.6 percent likelihood of reaching the postseason on Sept. 2. If they were to be surpassed by the Rays, it would rank prominently among the biggest collapses ever.

Yet while those gloom-and-doom prophecies have suddenly come to the fore, it is a bit premature to embrace the notion of their inevitability for a few reasons.

A) The Sox have gone down this road before. They got off to a 2-10 start that was puzzling because it didn’t align with their apparent talent. The Sox recovered from that 12-game struggle to produce the best record in the majors for several months to come.

B) The team’s outlook will change if Beckett and Bedard can return as healthy rotation contributors. Beckett is slated to throw a side session at Fenway on Monday; if that goes well, he’d likely start against the Rays. Of course, it remains to be seen whether Beckett or Bedard can pitch with their pre-injury effectiveness; nonetheless, it would be hard to imagine that they would downgrade the reeling rotation.

C) These sorts of seasonal ebbs and flows just … happen, at least on occasion.

The 2007 Red Sox exploded to a double digit lead in the AL East for the first half, then saw the advantage slowly dwindle to 1½ games over the Yankees in the final days of the year. But the Sox bounced back and earned the division title by two games, then went on to win the title.

The 2005 White Sox looked like they were collapsing, seeing a 15-game lead on Aug. 1 dwindle to a 1.5 game lead entering the season’s penultimate weekend. But they corrected course with wins in their last five games to make it to the postseason and, ultimately, to win it all.

The 2000 Yankees dropped seven straight to end the year, backing into the playoffs with an 87-74 record, but then rebounded in the postseason and won the World Series.

Put another way: it is far more common for teams to flirt with collapse than to experience it.

That, at least, is what history and numbers suggest. But right now, the Red Sox are playing like a team for whom nothing can be taken for granted. If the team can give away 4½ games in the standings in the span of one week, then it has to confront the reality that it can also find itself on holiday in October.

“Everything is just kind of going in a different direction at once. The good thing is we know how to figure that out and put it back together all at once,” Ortiz told reporters. “[But] it seems like everybody is in a funk right now, you know what I’m saying? There’s nobody to blame but everybody so hopefully on Tuesday we come back and play better.”